Purdue University is collaborating with General Motors to develop a new type of energy-absorbing material that might be 3D printed and could play an important role in the transportation, defense, and construction industries. The honeycomb architecture of the "phase transforming cellular materials," or PXCMs, could be scaled to a range of sizes tailored for various applications. One size could be ideal for integration into helmets to reduce head impacts, while another size would be suited for installation in the walls of buildings to dampen earthquake forces. Being able to 3D print the PXCMs would make them less expensive and more practical than other technologies. The PXCMs contain unit cells that have multiple stable configurations. The structures can flex back and forth and remain in either position indefinitely, not unlike a flexing playing card.